Crack paths in additive manufactured metallic materials subjected to multiaxial cyclic loads including surface roughness, HIP, and notch effects

Additive Manufacturing (AM) has recently gained much attention due to its many advantages. Nevertheless, design of critical load carrying parts via AM is still at its infancy because the damage mechanism and evolution of AM metals under,cyclic loading are not yet understood, particularly under complex multiaxial loading conditions. This work investigates fatigue cracking behavior of two AM metals including Ti-6Al-4V and 17-4 PH Stainless Steel and their wrought counterparts using both unnotched and notched tubular specimens. Cracking mechanisms and paths under a variety of conditions including annealing and HIPing processes, surface roughness, and build orientation are evaluated.